Differential cannabinoid-induced electrophysiological effects in rat ventral tegmentum

Cannabinoids are known to exert mainly excitatory effects on dopaminergic cells of the ventral tegmental area (VTA). We have utilized an in vivo multiple-single unit electrophysiological approach to assess different neuronal contributions that may ultimately lead to excitation in this area. Baseline neuron recordings, using low impedance microwires, showed a variety of waveforms with a wide range of durations (0.8-3.2 ms). In the first experiment systemic injection of the potent cannabinoid agonist HU210 (100 microg/kg, i.p.) led predominantly to an increase in firing rate (approximately 214%, compared to pre-drug) in slowly firing cells with broad action potentials, possibly driven by a majority of presumed dopaminergic neurons (n = 31). However, the firing rate of some units was either unaffected (<25%, n = 9) or even decreased (approximately 67%, n = 9) following cannabinoid injection concomitantly with excitation. Apomorphine (75 microg/kg, i.p.) injected following HU210 produced a marked inhibition of both responses (approximately 76%) in 39 out of 49 cells. The second group of animals was treated with the CB(1) receptor antagonist SR141716A (1 mg/kg, i.p.), which had no effect when injected alone but prevented all HU210-evoked changes in firing rate suggesting that cannabinoid receptors mediated the observed responses (n = 39). Taken together, the present results suggest that the observed actions of cannabinoids may involve complex neurotransmitter interactions leading to differential effects on dopamine release. These heterogeneous neuronal responses are likely to underly the behavioural discrepancies reported in animal models of cannabinoid reinforcement.     

Effects of D3.49A,R3.50A,and A6.34E mutations on ligand binding and activation of the cannabinoid-2 (CB2) receptor

In several G protein-coupled receptors (GPCRs), the Asp-Arg-Tyr (DRY) motif at the bottom of third transmembrane domain and the amino acid at position 6.34 in the sixth transmembrane domain have been shown to play important roles in signal transduction. In this study, we propose that in the cannabinoid-2 (CB2) receptor, R3.50 in the DRY motif may be crucial for interacting with G proteins, and D3.49 and A6.34 may be important for constraining the receptor in an inactive conformation. To test our hypothesis, R3.50A, D3.49A, and A6.34E mutations of the human CB2 receptor were made by site-directed mutagenesis. These mutant receptors were stably transfected into human embryonic 293 cells, and their ligand binding and signal transduction properties were analyzed. Similar to other GPCRs, R3.50 of the CB2 receptor is crucial for signal transduction. Unlike other GPCRs, D3.49 and A6.34 of the CB2 receptor do not seem to be important for keeping the receptor in an inactive state. Furthermore, D3.49A and A6.34E mutations abolished ligand binding, and all three mutations abolished constitutive activity of the wild-type CB2 receptor.     

MicroRNA-375 sensitizes tumour necrosis factor-alpha (TNF-α)-induced apoptosis in head and neck squamous cell carcinoma in vitro

We investigated the effect of microRNA-375 (miR-375) on tumour necrosis factor-alpha (TNF-α)-induced cell death in head and neck squamous cell carcinoma, and further explored the potential molecular mechanism underlying this phenomenon. Cal27 cells were transfected with miR-375 mimic and subsequently treated with or without TNF-α (10 ng/ml). An additional group of cells were treated with TNF-α alone. The resulting morphological changes were observed, and the percentage of sub-G1 cells was measured. The protein expression and cleavage of caspase 3, caspase 8, and poly(ADP ribose) polymerase (PARP) were determined through Western blotting. The results showed a significant increase in cell death in the combination group, but not in the groups treated with miR-375 mimic, TNF-α alone, or control. The data obtained from sub-G1 cells supported the notion that miR-375 increases the accumulation of sub-G1. In the combination group, the degradation of caspase 3, caspase 8, and PARP was observed and the cleavage of these enzymes was detected. The pan-caspase inhibitor, Z-VAD, inhibited the apoptosis of Cal27 cells treated with a combination of miR-375 mimic and TNF-α. In addition, the apoptosis inhibitory proteins, cFLIP-L and cIAP1, were down-regulated in a time-dependent manner. Taken together, these data suggest that miR-375 sensitizes TNF-α-induced apoptosis, and the reduction in the expression of the apoptosis inhibitory proteins cFLIP-L and cIAP2 plays an important role in this sensitization.     

Generalized ℋ︁2 model approximation for differential linear repetitive processes

This paper investigates the generalized ??₂ model approximation for differential linear repetitive processes (LRPs). For a given LRP, which is assumed to be stable along the pass, we are aimed at constructing a reduced‐order model of the LRP such that the generalized ??₂ gain of the approximation error LRP between the original LRP and the reduced‐order one is less than a prescribed scalar. A sufficient condition to characterize the bound of the generalized ??₂ gain of the approximation error LRP is presented in terms of linear matrix inequalities (LMIs). Two different approaches are proposed to solve the considered generalized ??₂ model approximation problem. One is the convex linearization approach, which casts the model approximation into a convex optimization problem, while the other is the projection approach, which casts the model approximation into a sequential minimization problem subject to LMI constraints by employing the cone complementary linearization algorithm. A numerical example is provided to demonstrate the proposed theories. Copyright © 2010 John Wiley & Sons, Ltd.     

人树突状细胞与K562细胞的融合以及体外诱导p210蛋白特异性CTL的研究

目的：探讨人外周血单细胞来源的树突状细胞（Ｄdndritic cells,ＤＣ）与人白血病细胞 Ｋ５６２融合后，能否诱导同p２１０蛋白特异性的ＣＴＬ，为ＤＣ疫苗的临床应用提供理 论基础。方法：外周血来源的巾附单核细胞，在人ＧＭ－ＣＳＦ（１０００Ｕ/ml）作用下，培养５～７天后，与人白血病细胞Ｋ５６２进行融合，融合细胞再与自体的淋巴细胞共同孵育１０～１４天，采用乳酸脱氢酶释放试验分析其对p２１０蛋白阳性细胞的杀伤效果。     

ℋ︁∞ control of discrete‐time Markov jump systems with bounded transition probabilities

This paper deals with the class of discrete‐time linear systems with random abrupt changes and unknown transition probabilities but varying between known bounds for each mode. The ℋ︁_∞ control problem of this class of systems is revisited and new sufficient conditions are developed in the linear matrix inequality (LMI) setting to design the state‐feedback controller that stochastically stabilizes the system under consideration and at the same time guarantees the disturbance rejection with a desired level γ . Sufficient conditions for existence of the state‐feedback controller are developed. It is shown that the addressed problem can be solved if the corresponding developed LMIs are feasible. Numerical examples are employed to show the usefulness of the proposed results. Copyright © 2008 John Wiley & Sons, Ltd.     

miR-210 agonist alleviates renal inflammatory response and fibrosis in diabetic kidney disease rats

Objective To investigate the protective effect and mechanism of microRNA-210 agonist (agomiR-210) on kidney in diabetic kidney disease (DKD) rats. Methods Thirty-six 5-week-old male SD rats were divided into normal control (NC) group, agomiR-NC control group, agomiR-210 control group, DKD model group, DKD+agomiR-NC group and DKD+agomiR-210 group, with 6 rats in each group. Diabetic rats were established by a high-fat diet combined with intraperitoneal injection of streptozotocin (STZ), then were fed for 12 consecutive weeks to construct DKD model rats. During 2nd-4th week of continuous feeding, the rats in DKD+agomiR-210 group were injected with 20 nmol/kg agomiR-210 via tail vein twice a week. Blood glucose levels, 24 h urine albumin (Alb) and 24 h urine microalbumin (MAU) contents were measured regularly. At the end of the 12th week, the rats were sacrificed, and renal tissues were collected. The renal histopathological changes were assessed by HE, PAS and Masson staining methods. The mRNA and protein expression levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-6 in renal tissues were detected by RT-qPCR and Western blot. The distributions and expressions of α-smooth muscle actin (α-SMA), typeⅠ collagen (Col-Ⅰ), type Ⅳ collagen (Col-Ⅳ) and fibronectin (FN) in renal tissues were detected by immunohistochemical method. The protein expression levels of phospho(p)-Smad3 and p-NF-κB p65 in renal tissues were detected by Western blot and immunohistochemical methods. Results Compared with DKD model group, the renal pathological damages in DKD+agomiR-210 group were improved, the blood glucose level, glycogen deposition and collagen accumulation were significantly decreased (all P＜0.05), the urinary excretions of Alb and MAU were significantly reduced (all P＜0.01), and the expressions of TNF-α, IL-1β, IL-6, α-SMA, Col-Ⅰ, Col-Ⅳ, FN, p-Smad3 and p-NF-κB p65 in renal tissues were significantly decreased (all P＜0.01). Conclusion AgomiR-210 can alleviate renal pathological changes and urinary Alb and MAU excretion in rats with DKD, which may be related to its inhibition of Smad3 and NF-κB activity.     

人体组织样品中钋-210的测定

本文介绍钋-210的分析程序。人体组织样品在硝酸-高氯酸体系中湿式浸取,在盐酸浓度0.5mol/L、温度95±2℃、转速550±50r/min 条件下,在20mm 铜片上自沉积2h。全程回收率82.5±3.0%。     

中国,日本等国40种香烟中铅—210 钋—210的测定

本文分析了中国、日本等国生产的40种牌号香烟中~(210)Pb,~(210)Po的含量。结果表明,中国香烟中~(210)Pb的含量变化范围为0.0289～0.0566Bq/g,平均值为0.0419Bq/g;~(210)Po的含量变化范围为0.0155～0.0568Bq/g,平均值为0.0349Bq/g。中国香烟中~(210)Pb,~(210)Po的含量高于日本等国生产的香烟。     

汉防己甲素联合屈洛昔芬对K562细胞bcr/abl表达的影响

为了研究汉防己甲素(Tet)联合屈洛昔芬(DRL)对K562细胞株凋亡相关因子bcr／abl mRNA及蛋白表达的影响，Tet(1μmol／L)和DRL(5μmol／L)单用及联合应用于K562细胞一定时间后，分别采用逆转录聚合酶链反应(RT—PCR)和Western blot方法检测K562细胞bcr／abl mRNA和蛋白表达的变化。结果表明：Tet和DRL单独应用对K562细胞bcr／abl mRNA及蛋白表达均无影响，两药联合应用于48小时K562细胞bcr／abl mRNA表达开始下调，K562细胞P^210 BCR／ABL蛋白表达于72小时开始下调。结论：Tet和DRL联合应用可下调K562细胞bcr／abl的表达，这可能是两药联用逆转耐药的机制之一。